Right heart failure occurs when the cardiac output from the right ventricle is not able to meet the demands of the body.
The most common cause of right heart failure is left heart failure. As the left ventricle fails, the pressures increase and transmit to the left atrium, the pulmonary veins, the pulmonary arterial system and eventually into the right heart. This can cause right heart failure. There are multiple causes of left heart failure as described in the systolic congestive heart failure review.
Causes of isolated right heart failure include severe lung disease (resulting in severe pulmonary hypertension), pulmonic/tricuspid valve disease, primary pulmonary hypertension, chronic pulmonary embolism, sleep related breathing disorders (obstructive sleep apnea) or right ventricular infarction.